1. Field of the Invention
This invention relates to a process for the production of silanes and more particularly, it is concerned with a process for the production of silanes, in particular, monosilane and/or chlorosilanes by disproportionation and/or redistribution reaction.
2. Description of the Prior Art
Silanes, in particular, monosilane is a raw material useful for the production of semiconductors, amorphous solar cells, IC devices and photosensitive materials. It is known that chlorosilanes or monosilane is obtained by the disproportionation or redistribution reaction of chlorosilanes as a raw material, as shown by the following formulas: EQU 2SiHCl.sub.3 .revreaction.SiH.sub.2 Cl.sub.2 +SiCl.sub.4 EQU 2SiH.sub.2 Cl.sub.2 .revreaction.SiHCl.sub.3 +SiH.sub.3 Cl EQU 2SiH.sub.3 Cl.revreaction.SiH.sub.4 +SiH.sub.2 Cl.sub.2
Thus, development or study of catalysts useful for these reactions has hitherto been carried out. These catalysts are insoluble solid anion exchange resins containing amino groups, etc. (Japanese patent application OPI (Kokai) No. 119798/1975), trimethylamine or dimethylethylamine (Japanese patent application OPI (Kokai) No. 121110/1984), palladium (Japanese patent application OPI (Kokai) No. 59230/1979), inorganic solid bases (Japanese patent application (Kokai) No. 174515/1984), compounds containing .alpha.-oxoamine groups (Japanese patent application OPI (Kokai) No. 54617/1984, tetraalkylurea (Japanese patent publication No. 14046/1980), .alpha.-pyrrolidones N-substituted by hydrocarbon groups (Japanese patent publication No. 14045/1980), cation exchange materials containing sulfonic acid groups (Japanese patent application OPI (Kokai) No. 164614/1984) and reaction products of amino alcohols and silica (Japanese patent application OPI (Kokai) No. 156907/1984). Furthermore, it is known that organo phosphorus compounds are useful for the disproportionation reaction of chlorosilanes. For example, quaternary phosphonium salts are described in Japanese patent publication No. 15529/1967, tri(monovalent hydrocarbon groups)phosphines are described in Japanese patent publication No. 18089/1965 and of late, similar proposals have been made in Japanese patent application OPI (Kokai) No. 60915/1985 by Tokuyama Soda Co., Ltd.
That is, the above described Japanese patent application OPI (Kokai) No. 60915/1985 proposes the use of an anion exchange resin consisting of a styrene-divinylbenzene type polymer combined with a tertiary phosphine as a catalyst. However, this catalyst has technical problems with respect to water resistance, chemical resistance, heat resistance and life at high temperatures and because of the short life at high temperatures, in particular, it is not favourably useful on a commercial scale.
As described above, the catalysts consisting of organic macromolecules combined with phosphino or phosphonium groups have already been proposed, but their activity tends to deteriorate readily under reaction conditions.